Toothbrush and process for producing such a toothbrush

ABSTRACT

The invention relates to a toothbrush having a handle and a head part, on which bristle filaments and at least one flexible cleaning element are arranged. The at least one flexible cleaning element is arranged on a carrier element, which consists of a hard material, and is connected to the head part. The invention also relates to a process for producing such a toothbrush.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a Division of application Ser. No. 10/362,590 filed Mar. 17,2003, which in turn is a National Stage of PCT/CH02/00717 filed Dec. 20,2002, which claims the benefit of German Patent Application No.10164336.5 filed Dec. 28, 2001. The entire disclosure of the priorapplications is hereby incorporated by reference herein in its entirety.

BACKGROUND

The invention relates to a toothbrush and for a process which isintended for producing the same.

Toothbrushes with a conventional bristle arrangement comprising clustersof bristle filaments, e.g. made of a polyamide (PA) or polyester (PBT),and an additional flexible structure are known, for example, from WO00/64307 and WO 01/21036. The conventional bristles here serve forcustomary teeth-cleaning purposes, while the flexible structure canperform different functions, e.g. massaging the gums, damping thecleaning movement, removing plaque, polishing the tooth surface,suspending the bristles in an elastic manner and/or sealing non-weldedlocations. WO 00/64307 discloses a toothbrush with rod-like flexiblecleaning elements which are of approximately the same length as theconventional clusters of bristles and are arranged on the periphery ofthe head part of the toothbrush. In the case of WO 01/21036, elasticcleaning elements are of sheet-like, e.g. undulating, configuration andare arranged within the conventional bristle arrangement. In the case ofWO 00/64307, a plurality of the flexible cleaning elements are connectedto one another via a material bridge made of the same material.

SUMMARY

Following the operation of covering the head part of the toothbrush withconventional bristles, the cleaning elements are produced by virtue ofthe head part being encapsulated by injection molding. The disadvantagehere is that the bristle filaments have to be prepared for use, e.g. byvirtue of the clusters of bristles being rounded or a predeterminedprofiling being produced, before the flexible structure is produced.Renewed insertion into the injection mold is then necessary in order toproduce the flexible structure. It is possible here for the clusters ofbristles to be damaged or contaminated. The elastic-structure shapeswhich it is possible to produce are limited, inter alia, for demoldingreasons.

The object of the invention is to provide a toothbrush, withconventional bristles and a flexible structure, which is straightforwardto produce. The intention is also to specify a corresponding productionprocess.

According to the invention, in the case of a toothbrush of the typementioned in the introduction, at least one flexible structure, e.g. acleaning element, is arranged on a carrier element which consists of ahard material. This carrier element is connected to the head part. Sucha toothbrush has production-related advantages since the additionalpart, i.e. the carrier element provided with the flexible structure, canbe produced separately and straightforwardly connected to the head part.

The connection between the carrier element and the head part may beproduced mechanically by clamping or snap-fitting or riveting,chemically by adhesive bonding, by ultrasonic welding, or thermally bywelding or other methods of supplying heat. It is preferred, in terms ofproduction, for the carrier element to consist of the same material asthe head part since, in this case, only one hard component need beprovided for producing the brush and there is no need to ensure materialcompatibility. This is advantageous, in particular, for ultrasonicwelding.

The arrangement of the flexible structure on a carrier elementconsisting of a hard material has the following advantages: theadditional part may be produced, and prepared for use, separately fromthe rest of the toothbrush body, comprising the handle and head part. Ina straightforward further step, the carrier element is connected to thehead part, it being possible to use any of the abovementioned connectingmethods and the hard carrier element preferably being formed inadaptation to the head part. The carrier element may be formed, forexample, such that, during the later connecting step, it engages aroundthe head part in a clamping manner. On account of the hard carrierelement, the additional part is easy to handle and can be grippedconsiderably more easily than an additional part produced entirely froma flexible material.

The additional part is small in comparison with the rest of thetoothbrush. The necessary molds are thus also small and cost-effective.The basic toothbrush body and the bristle covering may be produced usinga standard mold even if they are later provided with differentadditional parts. In order to produce toothbrushes with differentadditional parts, all that is necessary is to exchange the additionalpart and/or the corresponding mold therefor, which can be done in astraightforward and cost-effective manner.

A further advantage of producing the additional part and basic bodyseparately is that it is possible to realize any desired shapes offlexible cleaning elements, e.g. even those which cross over theconventional bristles, come into contact therewith or displace the samewhen the additional part is inserted. The separate production does notpose any problems for the demolding of the flexible structure. It ispossible to produce geometries by injection molding which would beextremely difficult to demold if the cleaning element were fitteddirectly on the bristle-covered head part.

Up until now, the flexible structure, for production-related reasons,has been produced from the same material as any flexible components onthe handle part. The invention provides a greater degree of freedom forthe material of the structure, with the result that it is possible touse, for example, a different degree of hardness.

A non-releasable connection between the additional part and the headpart prevents the additional part from detaching during use andeliminates the risk of swallowing.

The conventional bristles are fastened, for example, directly on thehead part, on a bristle plate acting as a further carrier element, oralso on the carrier element for the flexible cleaning elements, allvariants having advantages. During the operation of fastening thebristles on the head part or on the bristle plate, the flexiblestructure and the conventional bristles may be prepared independently ofone another for later use before the head part and additional part areassembled, with the result that they do not damage or contaminate oneanother.

The conventional bristles, in both cases, may be prepared for use beforeor after the flexible structure is fitted. If the two components areprovided on the carrier element, it is preferable first of all for theflexible structure, including any cleaning elements, to be integrallyformed and then for the carrier element to be covered with bristles,which may be guided, for example, through cutouts in the soft or hardcomponent.

Producing the additional part, i.e. the carrier element with one or moreflexible cleaning elements, preferably takes place by two-component ormulti-component injection molding. In this case, a non-releasableconnection is preferably produced between the components.

The flexible structure is preferably also arranged, e.g. molded,laterally on the carrier element, in which case, in the assembled state,it terminates laterally with the outer contour of the head part orprojects beyond the same. It serves, for example, for sealing non-weldedlocations, for massaging the gums, e.g. by way of molded-on elasticelements which project slightly, or as impact protection duringcleaning.

The flexible cleaning element preferably consists of an, in particular,thermoplastic elastomer, e.g. of natural or synthetic rubber. Thematerial used for the basic toothbrush body is preferably used for thecarrier element, in particular polypropylene, styrene-acrylonitrile,polyester, acrylonitrile-butadiene-styrene (ABS) or a polyurethane suchas Isoplast®. The Shore A hardness of the soft component is preferablyless than 90 and particularly preferably below 50.

The carrier element is particularly preferably covered with bristles byAFT (Anchor Free Tufting) technology. In this case, first of all, thehard-material carrier plate is produced with the flexible structure, inparticular by two-component injection molding. Then, the bristlefilaments are guided through cutouts in the carrier plate and/or in theflexible structure and, for fastening on the carrier plate and/or theflexible structure, are welded or adhesively bonded by way of their rearends, which in the application case are directed toward the brush head.This has the advantage that it is possible to realize largely anydesired bristle arrangements, in particular even sheet-like bristlestructures. The carrier element is connected to the head part, inparticular, by means of ultrasonic welding, e.g. as is described in DE200 06 311 U.

Since elastomeric material, in particular a thermoplastic elastomer, onaccount of the pronounced damping of the ultrasonic vibrations, can onlybe welded ultrasonically to a limited extent, the welding surfacebetween the carrier element and head part is preferably kept at leastpartially free of the flexible component. For this purpose, theinjection point of the soft component is preferably selected to be onthe bristle-carrying side of the carrier element, in order that nomaterial bridges from the soft component reduce the size of the weldingsurface. However, for the case where flexible elements are intended tobe arranged in the region of the welding surface, they are preferablypositioned to the side of the longitudinal axis of the toothbrush. Thislikewise produces non-welded locations laterally on the carrier element,while it is possible to weld the longitudinally front and rear regionsbetween the carrier element and head part. This ensures that the carrierelement is held well since the front and rear regions, in particular,and, to a lesser extent, the side regions, are subjected to loading bythe cleaning movement and the corresponding leverages. Merely punctiformwelding with non-welded locations may also be used specifically, inorder that the brush head and carrier element can be moved in relationto one another and a certain level of flexibility of the brush head as awhole is thus achieved.

It is also possible for the flexible structure, in the manner of asealing lip, to serve for the additional sealing of non-weldedlocations. As a result, the space between the carrier element and thehead part is advantageously sealed against the ingress of water. It isthus not possible for any germs to accumulate in this region, and thebrush is more hygienic. In order to achieve a reasonable sealingfunction, the Shore A hardness of the software component is preferablyless than 50.

BRIEF DESCRIPTION OF THE DRAWINGS

Examples for the invention are described hereinbelow and illustrated inthe drawings, in which, purely schematically:

FIGS. 1 a-d show views of a toothbrush according to the invention invarious assembly stages, the additional part being fastened on the headpart by riveting;

FIGS. 2 a-e show views of a further toothbrush of which the additionalpart is fastened by riveting;

FIGS. 3 a-e show views of a toothbrush of which the additional part isfastened by welding;

FIGS. 4 a-e show views of a toothbrush of which the additional part isfastened by means of a snap-fitting connection;

FIGS. 5 a-e show views of a further toothbrush of which the additionalpart is fastened by a snap-fitting connection;

FIGS. 6 a-f show views of a toothbrush in the case of which theadditional part is fastened in a clamping manner;

FIGS. 7 a-e show the production of a toothbrush by AFT;

FIGS. 8 a-e show views of a further toothbrush of which the additionalpart is fastened by a snap-fitting connection;

FIGS. 9 a-f show views of a further toothbrush, of which the additionalpart is fastened on the head part with play;

FIGS. 10 a-j show the production of a further toothbrush by AFT; and

FIGS. 11 a-c show views of a toothbrush with a lateral surround made offlexible material.

DETAILED DESCRIPTION OF EMBODIMENTS

All of the toothbrushes illustrated have a basic body with a head part 1and a handle part 2, which is only partially illustrated. An additionalpart 4 with a plurality of flexible cleaning elements 6 of differentshapes, which are connected to a carrier element of likewise differentshapes, is connected to the head part 1 when the toothbrush is in thefinished state. The head part 1, furthermore, is provided directly(FIGS. 1-5) or indirectly (FIG. 6) with clusters 3 of conventionalbristle filaments. The materials and arrangements of the clusters ofbristles 3 may vary. It is only the special features of the individualexemplary embodiments which are discussed hereinbelow, and elementswhich correspond to one another are provided with the same designations.

FIGS. 1 a and c show a toothbrush of which the head part 1 has alreadybeen provided with clusters of bristles 3. The additional part 4illustrated in FIG. 1 b has a sectionally U-shaped carrier element 5made of a hard material, in particular the same plastic which has beenused for producing the head part 1 and/or the entire basic body.Flexible cleaning elements 6, in this case in the form of straight rods,are firmly connected to the carrier element 5. The cleaning elements 6are inclined slightly out of the vertical, toward one another, andenclose an angle of from 5 to 30° with the vertical. In this way, theelastic cleaning elements 6 come into contact with the conventionalclusters of bristles 3 (FIG. 1 d) and may even cross over (notillustrated) the latter. Using conventional production processes, such aposition can only be realized with high-outlay displacement methods.

The carrier element 5 is adapted in shape to a cutout 9, visible in FIG.1 c, in that region of the head part 1 which is directed away from theclusters of bristles 3. Also located in this region are pins 7, whichcan be plugged through a hole 8 in the carrier element 5. The pins 7 arecold-formed or hot-formed and thus permanently fixed in the hole 8. FIG.1 d shows a plan view of the finished toothbrush.

For reasons of esthetics or hygiene, the bottom region of the hole 8 orof the head part 1 as a whole may be covered by a protective layer 22made of soft plastic (cf. FIG. 2 d). The boundary regions between thecarrier element 5 and the head part 1 are likewise preferably covered bysoft plastic. An example of the material used for this purpose is thesoft material which is also used for the handle region of thetoothbrush. The protective layer is preferably molded on during theproduction of the handle part by multi-component injection molding. Itis also possible, however, for the plastic layer to be integrally formeddirectly on the carrier element.

A further example of a toothbrush of which the additional part 4 isconnected to the head part 1 by riveting is illustrated in FIGS. 2 a-e.The additional part, in this case, comprises a plate-like carrierelement 5 to which sheet-like flexible cleaning elements 6 are connectedin the form of a rosette. The carrier element 5 has a pin 7′ by means ofwhich the additional part 4 can be plugged through a correspondinglyprepared hole 8′ in the front end of the head part and can be fixed byvirtue of the pin 7′ being deformed. The flexible cleaning elements 6are located in the region of the tip of the head part 1. The bristlearrangement with individual clusters of bristles 3 follows in thedirection of the handle part 2. A protective layer 22 covers the regionof the hole 8′.

FIGS. 3 a-e show a further example of a toothbrush, which ends upsimilar to a toothbrush according to FIG. 2. The additional part 4 witha plate-like carrier element 5 and rosette-like flexible cleaningelements 6, in this case, is connected to the head part 1 by welding.For this purpose, the front region of the head part has a plate-likecutout into which the carrier element 5 is permanently introduced, byway of a correspondingly structured underside 5 a, by means ofultrasonic welding. FIG. 3 d shows a side view of the finishedtoothbrush, and FIG. 3 e shows the plan view of the combined bristlearrangement comprising conventional clusters of bristles 3 and flexiblecleaning elements 6.

The additional part 4 of the toothbrush illustrated in FIGS. 4 a-e isfastened in the center of the head part 1 by means of snap-fitting. Theadditional part 4 comprises a rectangular carrier element 5 withwing-like flexible cleaning elements 6 arranged at its corners. Tworod-like cleaning elements 6 are also located on the carrier element 5(FIGS. 4 b and c). As is illustrated in FIG. 4 a, the head part 1 has acentral hole 8″, through which a resiliently configured extension 11 onthe carrier element 5 is plugged. The additional part 4 and head part 1are connected to one another by a snap-fitting connection which, onaccount of the enlarged cross section at the bottom end 11 a of theextension 11, cannot readily be released. The bristle arrangement of theconventional clusters of bristles 3 is configured such that thewing-like cleaning elements 6 are positioned between the conventionalclusters of bristles 3, as is illustrated in FIGS. 4 a and 4 e. Theadditional part 4 is produced separately and then inserted into the headpart 1 with the prepared bristle arrangement. It is thus also possibleto realize structures of the flexible cleaning elements 6 which engagethrough the convention bristle arrangement, such as the diagonallyarranged wing-like elements from FIGS. 4 b-e or the fanned-out pin-likecleaning elements, oriented in different directions in space, from FIG.8. For reasons of hygiene or esthetics, the underside of the head part 1is covered by a layer 22 made of flexible material.

FIGS. 5 a-e show a further example of a snap-fitting connection betweenthe additional part 4 and the head part 1 of a toothbrush according tothe invention. Within the bristle arrangement made of conventionalclusters of bristles 3, the head part 1 has a prepared region 13 foraccommodating the additional part 4. This region 13 comprises adepression with a groove 12 running on the border of the latter in eachcase, perpendicularly to the alignment of the handle 2, said groove 12providing the head part 1 with a certain level of elasticity orresilient action, as do also the grooves 12′ running on the lateralborder of the head part. The prepared region 13 is slightly smaller thanthe basic surface area of the carrier element 5, with the result thatthe latter can be fitted into the region 13 in a clamping manner. As canbe seen from the plan view in FIG. 5 e, the additional part has bothrod-like cleaning elements and sheet-like cleaning elements arrangedtransversely to the alignment of the handle 2.

FIGS. 6 a-f show a further example of a toothbrush according to theinvention, in this case a plug-on toothbrush for an electricteeth-cleaning unit. The conventional clusters of bristles 3 arefastened on a separate bristle plate 18 which, in the assembled state,is connected to the matching head part 1 of the toothbrush or a disc 23which is fastened in a rotatable or pivotable manner thereon. Theflexible cleaning elements 6, which are rod-like in this case, arefastened on a carrier element 5 which is slightly curved in plan viewand has a sheet-like extension 16, which is oriented essentiallyperpendicularly to the alignment of the cleaning elements 6. Theadditional part 4 can be introduced, by way of said extension 16, into acorrespondingly shaped groove 14 in the disc 23. Arranged in the centerof the head part 1 and of the groove 14 is a round cutout 15, in which acorresponding mating element 17 on the extension 16 of the additionalpart 4 engages. The additional part 4 and head part 1 are thus connectedto one another in a well-fitting and clamping manner. At its bottom end,the bristle plate 18 has a groove 19 by means of which the bristle plate18 can be fastened on the disc 23 or the lateral extensions 23 thereof.In the embodiment illustrated, the additional part 4 is moved along bythe disc 23. As an alternative, it is possible for the additional part 4to be fastened directly on the head part 1 and not to rotate as well.

FIGS. 7 a-e show an example of the production of a toothbrush by meansof AFT technology. FIGS. 7 a-c show sectional views of the carrierelement 5 in various process stages, to be precise before being providedwith flexible cleaning elements 6 and conventional clusters of bristles3 (FIG. 7 a), following the application of the flexible material (FIG. 7b) and following the application of the bristles (FIG. 7 c). The outershape of the carrier element 5 is adapted to the dimensions of aprepared region 13 in the form of a shallow cutout in the head part 1 ofthe toothbrush. The carrier element 5 has prepared regions 20, intowhich the flexible cleaning elements 6 are fitted, in particular molded.Furthermore, the carrier element 5 has cutouts 24, which are filledwholly or partially with flexible material 6′, see also the detail fromFIG. 7 e. The carrier element 5 also contains holes 21, through whichclusters of bristles 3 are plugged and are fastened on the rear side byvirtue of their rear ends 3 a being incipiently melted. The elasticmaterial regions 6′ have further holes 21′ which likewise serve foraccommodating clusters of bristles 3, which are fastened in the sameway. The material regions 6′ can accommodate one or more clusters ofbristles 3. The clusters of bristles 3 anchored in the elastic material6′ are thus anchored or suspended in a particularly elastic manner.Further clusters of bristles 3 are fastened directly on the carrierelement 5. The carrier element 5 fitted with clusters of bristles andthe flexible structure 6, 6′ is then inserted into the prepared region13.

The edge 30 of the carrier element 5, this edge in the application casebeing directed towards the base of the cutout 13, is tapered, just as inthe example from FIGS. 10 and 11. This tapering edge 30 serves, duringultrasonic welding for connection to the head part 1, as an energyconcentrator and a material reservoir for material which is to beliquefied.

The AFT technology manages without anchors or clips for fastening thebristle filaments, which instead are welded directly on the carrierplate. This means that the width of a cluster of bristles is notdetermined by the anchor, with the result that it is also possible torealize finer structures, in particular also sheet-like bristlearrangements.

It is technically also possible, in the case of AFT, to prepare thebristle filaments for use before they are fitted on the carrier plate.The variant which is realized at present, however, is that where thebristles are only machined once they have been fitted on the carrierplate.

FIGS. 8 a-e show a variant of the toothbrush from FIG. 4. The bristlearrangement made of conventional clusters of bristles 3 corresponds toFIG. 4. The additional part 4 has a plurality of pin-like cleaningelements 6 which diverge in the form of a star and engage through theconventional clusters of bristles 3 (FIGS. 8 d and e). The fasteningmechanism corresponds to FIG. 4. A layer 22 made of flexible materialcovers the underside of the head and handle parts 1, 2. FIGS. 9 a-f showa further example of a toothbrush according to the invention. The headpart 1 has a prepared region 13 for the carrier element 5 of theadditional part 4, said region being larger than the carrier element 5itself. The region 13 is, for example, a hole which passes all the waythrough the head part 1, see sectional drawings from FIGS. 9 b, d and e.The region 13 has two lateral grooves 13 a, the shape of which isadapted to the shape of two lateral extensions 5 b of the carrierelement 5. The latter is inserted into the head part 1 and latchesthere. The play of the carrier element 5 within the region 13, whichallows lateral displacement and/or a pivoting movement about the axisdefined by the extensions 5 b, results in a particular level ofelasticity or resilient action of the additional part 4. The rear sideof the head part 1, again, may be covered by a layer of soft material.

FIGS. 10 a-j show a further example of a toothbrush produced by means ofAFT. FIGS. 10 a-c correspond to FIGS. 7 a-c and each show the carrierplate 5 in various process stages. FIGS. 10 d-f show the same carrierplate 5 in section along line I-I indicated in FIG. 10 a. The centrallyarranged flexible element 6 is sheet-like or sail-like and is undulatingin plan view (FIG. 10 h). As is illustrated in FIGS. 10 e and f, theflexible structure comprises laterally integrally formed regions 6″which, in the assembled state (FIG. 10 h), bound the toothbrush head 1laterally and terminate more or less flush with the outer contour of thehead part. They serve, for example, as impact protection and/or foradditionally massaging the gums. The regions 6″ likewise have holes 21′for accommodating clusters of bristles 3, which are thus suspended in anelastic manner and are particularly compliant during cleaning.

The carrier element 5 provided with conventional bristles 3 and theflexible structure 6, 6′, 6″ is inserted into a cutout 13 in the brushhead 1. The brush head 1 is illustrated in various views without thecarrier element 5 in FIGS. 10 g and j and with the carrier element 5inserted in FIGS. 10 h and i. On its lateral border, the brush head 1 orthe cutout 13 has lateral openings 25, which are adapted to the lateralflexible regions 6″ previously molded on the carrier element 5.

The carrier element 5 is connected to the brush head 1 by means ofultrasonic welding. The welding surface 26 is indicated by dashed lines.In order to realize the welding, the carrier element has, on its bottomborder, a welding border 26′ which, during assembly, rests on the baseof the cutout 13, the contact surface defining the welding surface 26.The welding border 26′ melts under the influence of ultrasound, with theresult that the two parts 5 and 1 are connected to one another.

Since elastomeric material can only be welded ultrasonically to alimited extent, the welding surface 26, as far as possible, is kept freeof this material, for example as in the case of the toothbrush from FIG.7 or, with only minimal interruptions, as in the case of the toothbrushfrom FIG. 10. The aim, in both cases, is to seal the cavity 28 betweenthe carrier element 5 and head part 1 to the full extent, in order toprevent the ingress of water and germs. For this purpose, the injectionpoint of the flexible material is preferably selected to be on thebristle-carrying front side of the carrier element 5, in order that nounnecessary material bridges reduce the size of the welding surface 26.If further flexible elements are provided on the head part 1, inparticular on the rear side thereof, they are positioned such that theydo not reduce the size of the welding surface 26. For example, theseelements and the corresponding injection point are located fully withinthat region on the rear side of the head part 1 (not illustrated) whichis defined by the welding surface 26. The entire contact surface betweenthe head part 1 and carrier element 5 is preferably welded over at least25%, particularly preferably along the periphery of the head (line 26).

In the example from FIG. 10, the flexible regions 6″ interrupt thewelding surface 26, with the result that non-welded locations 27 areproduced there. These are advantageously arranged on the side of thehead part 1, while the longitudinally front and rear regions of thecarrier element 5 are firmly welded to the head part 1. This ensuresthat the carrier element 5 is held securely since the front and rearregions are subjected to an extremely high level of loading by thecleaning movement and corresponding leverages.

The non-welded locations 27 are sealed by the flexible regions 6″ herein the manner of a sealing lip, with the result that only a very smallamount of water, if any at all, can penetrate into the cavity 28. For agood sealing function, material with a Shore A hardness of 50 or less ispreferably selected. Non-welded locations between the head part andcarrier element may also be used specifically, in order to achieve acertain level of flexibility between the two hard components.

FIG. 11 shows various views of a further example of a toothbrushproduced by AFT, in this case, with two sail-like flexible cleaningelements 6. The carrier element 5 is fully enclosed, around itsperiphery, by flexible material 6′, which, in the assembled state(plan-view illustration FIG. 11 a) fully encloses the outer periphery ofthe head part 1 on the top side and serves as impact protection. Inregions 6″, the soft material serves as a mount for lateral clusters ofbristles 3 which are guided through the flexible material 6″.

As can be gathered from FIG. 11 c, the hard components (carrier element5 and head part 1) come into contact with one another along a surface 26beneath the soft component in the region 6′ and can be welded here bymeans of ultrasound. The welding surface 26 is interrupted by thelateral regions 6″, although, as has been described above, a sufficientretaining action is achieved. The cavity 28 beneath the carrier element5 is sealed by the flexible regions 6″ and the locations welded alongthe surface 26.

The method of welding and sealing the components which has beendescribed above with reference to FIGS. 10 and 11 may alsoadvantageously be used for other toothbrushes.

1. A toothbrush, comprising: a handle and a head part with bristlefilaments and a flexible structure, wherein the flexible structure isattached to and/or part of a plate-like carrier element which has afront side and a rear side, the carrier element being of a hardermaterial than that of the flexible structure and connected to the headpart such that a rear side faces the head part, wherein bristlefilaments are guided through bristle receiving cutouts in the carrierelement and/or in the flexible structure, and rear ends of the bristlefilaments are melted, welded or adhesively bonded on the rear side ofthe carrier element or the flexible structure.
 2. A toothbrush asclaimed in claim 1, wherein a non-releasable connection is providedbetween the carrier element and the head part.
 3. The toothbrush asclaimed in claim 1, wherein the carrier element consists of the samematerial as the head part.
 4. The toothbrush as claimed in claim 2,wherein the non-releasable connection provided between the carrierelement and head part is produced by clamping, snap-fitting, riveting,adhesive bonding, welding, ultrasonic welding or the supply of heat. 5.The toothbrush as claimed in claim 1, wherein the flexible structure andthe carrier element are produced by multi-component injection moldingand mated with a non-releasable connection.
 6. The toothbrush as claimedin claim 1, wherein the material of the carrier element is polypropylene(PP), styrene-acrylonitrile (SAN), acrylonitrile-butadiene-styrene(ABS), polyurethane (PU) or polyester (PET).
 7. The toothbrush asclaimed in claim 1, wherein the head part comprises a carrier elementreceiving cutout adapted to the shape of the carrier element and whereinthe carrier element is inserted into said carrier element receivingcutout and connected in a non-releasable manner to the head part.
 8. Thetoothbrush as claimed in claim 1, wherein the flexible structureincludes natural or synthetic rubber.
 9. The toothbrush as claimed inclaim 1, wherein the flexible structure includes a thermoplasticelastomer.
 10. The toothbrush as claimed in claim 1, wherein theflexible structure has a Shore A hardness of less than
 90. 11. Thetoothbrush as claimed in claim 1, wherein the flexible structurecomprises at least one flexible, non-bristle containing cleaningelement.
 12. The toothbrush as claimed in claim 11, wherein the carrierelement comprises at least one cleaning element receiving cutoutextending at least partially through the carrier element, wherein saidnon-bristle containing cleaning element is anchored in the cleaningelement receiving cutout.
 13. The toothbrush as claimed in claim 12,wherein the bristle receiving cutouts are arranged directly in thecarrier element and provided with bristle filaments.
 14. The toothbrushas claimed in claim 11, wherein the non-bristle containing cleaningelement comprises sheet-like elements that are arranged centrally on thecarrier element.
 15. The toothbrush as claimed in claim 1, wherein atleast one of the bristle receiving cutouts is arranged in the flexiblestructure and provided with bristle filaments that are anchored to theflexible structure in an elastic manner.
 16. The toothbrush as claimedin claim 15, wherein a plurality of bristle receiving cutouts arearranged in a common region of the flexible structure and provided withbristle filaments such that a cluster of neighboring bristle filamentsis formed.
 17. The toothbrush as claimed in claim 15, further comprisingbristle receiving cutouts arranged directly in the carrier element, thecutouts being provided with bristle filaments.
 18. The toothbrush asclaimed in claim 1, wherein contacting locations between the head partand the carrier element are covered with flexible material.
 19. Thetoothbrush as claimed in claim 1, wherein the flexible material sealsthe contacting locations against entry of water.
 20. The toothbrush asclaimed in claim 1, wherein the flexible structure comprises regionsarranged laterally on the carrier element, said regions terminatinglaterally with the outer contour of the head part or projecting beyondthe same when the carrier element is attached to the head part.
 21. Thetoothbrush as claimed in claim 20, wherein said regions seal contactinglocations between the head part and the carrier element against theentry of water.
 22. The toothbrush as claimed in claim 20, wherein thehead part comprises at least one lateral opening having a shape adaptedto the regions arranged laterally on the carrier element.
 23. Thetoothbrush as claimed in claim 1, wherein the carrier element comprisesan edge on its rear side that acts as a welding border during ultrasonicwelding by contacting the head part during assembly and melting underthe influence of ultrasound to connect the carrier element to the headpart.
 24. The toothbrush as claimed in claim 23, wherein the edge istapered.
 25. The toothbrush as claimed in claim 23, wherein the flexiblestructure is arranged within the area defined by the welding border. 26.The toothbrush as claimed in claim 23, wherein the welding border iskept free of the flexible material.
 27. The toothbrush as claimed inclaim 5, wherein an injection point for producing the flexible structureis on the front side of the carrier element.
 28. A process for producinga toothbrush comprising: providing a handle and a head part; providing acarrier element having a front side and a rear side; attaching aflexible structure to the carrier element, wherein the carrier elementis made from a harder material than that of the flexible structure;providing a plurality of bristle filaments and guiding them throughbristle receiving cutouts in the carrier element and/or in the flexiblestructure; fastening rear ends of the bristles on a rear side of thecarrier element and/or the flexible structure by melting, welding oradhesive bonding.
 29. The process as claimed in claim 28, furthercomprising connecting the carrier element and the head part to oneanother in a non-releasable manner.
 30. The process as claimed in claim28, further comprising connecting the carrier element and the head partby clamping, snap-fitting, riveting, adhesive bonding, welding,ultrasonic welding or the supply of heat.
 31. The process as claimed inclaim 28, further comprising cutting and/or rounding the bristlefilaments after fastening of the bristles to the carrier element and/orthe flexible structure and before fastening the carrier element to thehead part.
 32. The process as claimed in claim 28, further comprisingcutting and/or rounding the bristle filaments before fastening of thebristles to the carrier plate and/or the flexible structure.
 33. Theprocess as claimed in claim 28, comprising producing the flexiblestructure and the carrier element by two-component injection molding.34. The process as claimed in claim 28, comprising producing anon-releasable connection between the flexible structure and the carrierelement.
 35. The process as claimed in claim 28, further comprisinginserting the carrier element into a cutout in the head part andconnecting the carrier element in a non-releasable manner to the headpart after the bristle-fastening operation and the attachment of theflexible structure.
 36. The process as claimed in claim 28, furthercomprising providing an injection point of the flexible material on thefront side of the carrier element.
 37. The process as claimed in claim28, further comprising producing the carrier element with a rear edgeand connecting the rear edge to the head part by ultrasonic welding,wherein the rear edge is directed toward the head part and serves as awelding border during ultrasonic welding.
 38. The process as claimed inclaim 37, further comprising welding together a contacting area betweenthe head part and the carrier element at an extent of at least 25% ofthe contacting area.
 39. The process as claimed in claim 37, furthercomprising welding together the head part and the carrier element in afront and a rear region, relative to a longitudinal direction of thehead part, and leaving lateral regions unwelded.
 40. The process asclaimed in claim 37, further comprising welding together the head partand the carrier element at point-like locations and leaving regionstherebetween unwelded.
 41. The process as claimed in claim 37, furthercomprising welding together the head part and the carrier element alongthe circumference of the carrier element, thereby leaving certainregions unwelded.
 42. The process as claimed in claim 28, furthercomprising sealing contacting locations between the head part and thecarrier element with flexible material.